On September 22-23, 2000 (Fri-Sat), Caleb E. Finch and Robert E. Ricklefs plan to convene a Symposium on Organisms with Slow Aging (SOSA) at the Andrus Gerontology Center, University of Southern California. SOSA will critically examine the emerging evidence that some multi-cellular organisms have evolved very slow rates of aging with anti-aging mechanisms that are pertinent to human aging processes. Rates of aging can be evaluated by recognized criteria: demographic (age-specific mortality rates and fecundity); molecular (oxidative damage and telomere DNA length); and cellular-physiological changes, e.g. clonal life span, cell turnover, and organ functions. Examples from vertebrates, invertebrates, and vascular plants show a range of long life spans, which overlap with, or exceed, the upper ranges of human life spans. Field data for mortality and reproduction are available for certain in long-lived fish, turtles, and birds. The complex biology of long-life spans will be discussed in terms of evolutionary theory. Speakers will identify sources of data and availability of biological specimens to stimulate research and attract new scientists and trainees. The program includes a volunteer poster session. The specific aims of the meeting are to find a common basis for discussing the biology of long life spans in a variety of animal and plant models; organize the building of a comparative database for demographic and physiological aging parameters; and recruit new investigators and trainees to the comparative study of organisms with extended reproductive schedules and extreme longevity.